Method of coating active material with flake-like conducting material.



' which canbe carried out e cured, and all the particles will have an equal I N TED STATES PATENT oEEIoE.

-THOMAS A; EDISON. or LLEWELLYN PARK, ORANGE, NEW JERSEY, ASSIGNOR TO 'EDISON STORAGE BATTERY COMPANY, or wEsr ORANGE- NEW JERSEY, A CORPORATION OF NEW JERSEY METHOD OF COATING ACTIVE MATERIAL WITH FLAKE-LIKE CONDUCTTNG MATERIAL Specification of Letters Patent.

Patented Doc. 25, 1906.

Application 5166. mm so, 1905. Serial No. 252.931.

of which the following flake-like conductinamaterial-such as flake graphite or flake nic el, or cobalt, or an alloy of nickel and cob alt for use in connection with the manufacture of the positive electrodes of my improved storage battery.

My present invention resents a process ectively with flakelike conducting material even when the latter is of a very friable nature, as is the case with electrodeposited nickel or cobalt films, and since practically no pressure is utilized in the mixing operation there can be no objectionable of the nickel or cobalt if used. Furthermore, the resulting cake or mass of active material is of such a character that good contact throughout its entire mass is seopportunity of bemg acted upon by the current. The active mass will present innumerable paths through which the current may traverse, permitting all the particles of active material to be reached and acted upon by the current.-

In carrying my invention into effect I proceed substantially as follows: A suitable nickel compoundsuch as the hydroxid thereof, obtained in any suitable wayis first ground so as to present particles of substantially a definite size, ranging, say, between those which pass a twenty-mesh screen and are arrested by a sixty-mesh screen. To the active mass 1. hen mix a sufficient uantity of a suitable sticky material unt' the surfaces of tne active particles are covered with a thin layer of the sticky material. The preferred sticky material used is molasses,

whichis cheap and can be readily removed by washing; but obviously any other suitable material for the purpose The mixing of the sticky active mass is preferably effected in a suitable mixer wherein little or pl,ied-such, for example,

inrmy Patent After the sticky material has been intimatel mixed with the active mass and while pref erably in the mixer conducting films or plates.

ber of small may be employed. material with the no pressure is apas that described No. 605,668, of June 14, 1888.

I add the flake-like conducting material-such as flake graphite, or flake-like metallic nickel, or cobalt, or

nickel-cobalt alloys-and continue the mixing until practically the whole exposed surfaces of all the active particles are covered with the croscope it has been observed that frequently a single particle may be. covered with a numflakes adhering to the facets of the particles, and in some instances the flakes or foils are actually bent around the particles, so as to wholly or partiallyenvelop the same without, however, preventing the free escape of gas. Whatever the particular'disposition of the flakes or scales upon or with respect to the active particles may be the fact is that by the process described the "active particles are practically covered as to their entire surfaces by flakes or scales ofthe conducting material. Suitable roportions which may be employed are eig t parts, by weight, of nickel hydroxid and two parts, by weight, of the flake-like conducting material. With these proportions the continued mixing as described results in the complete covering of the active particles, as explained, so that the entire mass uniformly presents the ap earance of being composed wholly of the flakelike conducting substance.

After the mixing operation the mass. is dried and is then applied in the usual way to the pockets of the battery-grid and subjected to a moderate pressure, generally about onethird of that ordinarilyemployed, or about two thousand pounds per pocket. This pressure is sufficient to hold the owdered mass in position, and in this con 'tion the electrodelates are immersed in water, slightly al aline, to prevent rust and the molasses thoroughly dissolved out. Athorough dissolution of the sticky material generally requires several changes of water and takes place in about forty-eight hours. The plate is now thoroughly dried, and the final Under the mi- I pressure (about six thousand pounds per j pocket) is applied to lock the pocket-sect1ons in place, after which the electrode is ready to j be assembled in the battery.

Having now described my invention, what 1 claim as new therein, and desire to secure by Letters Patent, is as follows: i

1. The process of covering active particles with flake-like conducting material, which includes adding a sticky material to and mixing the same with the active particles, wherej by a sticky film will be applied to each partij cle, andin then mixing a flake-like material with the coated active particles, whereby the scales or flakes of the former will cover the individual particles of the active material, substantially as set forth.

2. The process of covering active particles with flake-like conducting material, which includes adding molasses to and mixing the 1 same with the active particles, whereby a sticky film will be applied to each particle, j and in then mixing the flake-like material i with the coated active particles, whereby the j scales or flakes of the former will cover the individual particles of the active material, substantially as set forth.

3. The process of covering active particles with flake-like conducting material, which includes adding a sticky material to and mixing the same with, the active particles, whereby a sticky film will be applied to each particle, in then mixing a'flake-like material with the coated active particles, whereby the scales or flakes of the former will cover the individual particles of the active material, then in applying pressure to the mixture so obtained, and in then removing the sticky material, substantially as set forth.

4. The process of covering active particles with flake-like conducting material, which includes adding a sticky material to and mixing the same with the active particles, whereby a sticky film will be applied to each particle, in then mixing a flake-like material with the coated active particles, whereby the flakes or scales of the former will cover the individual particles of the active material, then in applying pressure to the mixture so obtained, and in then soaking thecompressed mass in a solvent of the sticky material, l whereby the latter will be dissolved and eliminated, substantially as set forth.

5. The process of covering active particles with flake-like conducting material, which includes adding a sticky material to and mixing the same with the act ivc particles whereby a sticky him will be applied to each particle, in then mixing a flake-like material with the coated active particles, whereby the scales or flakes of the latter will cover the individual particles of the active material, in then drying the mass, subjecting the same to a moderate pressure and in then removing the stickymaterial, substantially as set forth.

6. The process of covering active particles with flake-like conducting material, which includes adding molasses to and mixing the same with the active particles, whereby a sticky film will be applied to each particle, in then mixing the flake-like material with the coated active particles, whereby the scales or flakes of the latter will cover the individual particles of the active material, in then drying the mass, subjecting the same to amoderate pressure and then dissolving out the molasses, substantially as set forth.

7. The process of covering active particles with flake-like conducting material, which includes adding molasses to and mixing the same with the active particles, whereby a sticky film will be applied to each particle, in then mixing-the flake-like material with the coated active particles, whereby the scales or flakes of the latter will cover the individual particles of the active material, in then drying the mass, subjecting the same to a moderate pressure and in then dissolving out the molasses in alkaline water, substantially as set forth.

8. The process of covering active particles with flake-like conducting material, which consists in adding molasses to and mixing the same with theactive particles whereby a sticky film will be applied to each particle, in then mixing the flake-like material with the coated active particles, whereby the scales or flakes of the latter will cover the illdividual particles of the active material, in then drying the mass, subjecting the same to a moderate pressure and in finally subjecting the material to the desired final pressure, substantially as set forth.

This specification signed and witnessed this 29th day of March, 1905.

THOMAS A. EDISON.

Witnesses:

FRANK L. DYER, ANNA R. KLEHM. 

